Explanation The presentation layer (ISO/OSI layer 6) performs transformations on data to provide a standardized application interface and to provide common communication services such as encryption, text compression and reformatting. The function of the presentation layer is to ensure that the format of the data submitted by the application layer conforms to the applicable network standard. Reference: Information Systems Audit and Control Association, Certified Information Systems Auditor 2002 review manual, Chapter 3: Technical Infrastructure and Operational Practices (page 119).